You’d heard it in its highest pitch on the rap legend’s tracks, between his muscular rhymes, but off the mic it sounds heartier, more devil-may-care and less of a snickering giggle. It’s the laugh of a man who’s been down, and way up, and will stay way up until he’s in the grave, and he knows that you know this, too.

Aside from a still-ticking recording career, Jackson is the proud owner of upstart boxing promotion-outfit SMS Promotions and the founder and CEO of SMS Audio, a consumer electronics manufacturer of headphones and audio products. Launched in 2011, the latter enterprise is aiming to seize control of the premium headset marketplace that it shares with Beats by Dre with two sports-related ventures. One is an equity ownership and ambassadorial deal, signed in December, with New York Knicks star Carmelo Anthony. The new, more surprising pact, announced Tuesday, pairs 50 Cent with Swan Racing as an associate sponsor on the stock-car team’s No. 26 and No. 30 Toyota Camrys during the 2014 and 2015 NASCAR Sprint Cup Series seasons.

The new partnership will include SMS Audio branding on the two cars and on their drivers’ uniforms, as well as Swan-branded headphones featuring his wheelmen, Cole Whitt and Parker Kligerman. You can also look for 50 Cent at races throughout the season.

The former pugilist and Knicks lifer called me Monday for an exclusive and wide-ranging interview that covered the New Yorker's NASCAR venture, boxing promotion, upcoming album, as well as his thoughts on the Bieber-Floyd duo, Melo and the Knicks, Kobe and the Lakers, and his fear of Meryl Streep. Apparently some things, like the Oscar-winning actress, can scare 50 Cent.

[Editor’s note: this interview includes mature language.]

50, let’s start with the NASCAR deal. If we were playing a name association game where somebody says “NASCAR,” I’d never in a million years utter “50 Cent.” How did this venture come about?

[Laughs] Well, it’s collaboration between SMS and Swan Racing. I attended the Daytona 500 last year and there was so much publicity -- and an awkward moment: I was saying hi to [reporter] Erin Andrews and she turned around right at the same time, and I almost kissed her. It got 10 million views online. And I enjoyed myself [at the race] and I became open to the idea. I watched it a lot on TV and hung out with [drivers] at parties, but that was the first race I actually attended.

What is it about the sport that appeals to you?

I liked NASCAR before I knew what it was. I had toy cars as a kid. I developed a fetish. Listen, parents paint the room pink for a girl, blue for a boy, and if they’re buying a toy for a boy, it’d be a car. I’d actually cry if I didn’t have my cars. So I already had that fascination.

Say no more -- I loved my Hot Wheels.

They did it to you, too. [Laughs] I love those little cars that you roll and you make the noise.

I’m picturing Little 50 making engine noises for his toy cars.

[Laughs.] Yup, just manual car movement back then.

What was it about Swan Racing that made them a good fit for SMS?

It’s a young company, and they got really good drivers with something to prove. The Seahawks showed us in the Super Bowl that a young team can make things happen. We got two drivers that SMS will be connected to: Cole Whitt and Parker Kligerman. They’re both in the running for rookie of The year. They’re hungry. You want to be attached to that. Sometimes, people in a good spot become complacent. You won’t outwork these guys. I’m conscious of that.

I’d imagine few things in this world scare you. Is racing around a NASCAR track one of them?

For people who haven’t been to a race, I urge them to get out there. I thought I knew what it was, watching it on TV. But when you go there, you can feel the car moving around the track. It gives you a new perspective. I have a car collection myself.

What’s the fastest car you've got?

Right now, I got a Lamborghini. I don’t actually race it. But the Porsche [911] Turbo is fast. I’d rather race the Porsche Turbo on an actual track.

What’s the fastest you’ve ever driven?

You mean on the highway? Like 120 mph.

I won’t tell anybody.

Naw, it was late night! I ain’t got no ticket -- how you gonna confirm it? [Laughs.] You know I entertain people. Well, I was doing that for entertainment.

As part of the agreement with Swan Racing, rapper 50 Cent will make appearances at NASCAR races throughout the season. Jeff Siner/Getty Images

NASCAR isn’t exactly known for its diversity, in terms of fans or drivers. Does that trouble you, or is that perhaps a part of the appeal for you, or both?

Yeah, for me to be in this space, it’s not common for them to do this. With their tradition in marketing, you end up -- where you have huge success is when you go outside of that cookie-cutter mentality and the norms. Hip-hop culture is exposed to the point where it’s pop culture now. Even skateboarding is a part of hip-hop culture. So a lot of viewers of NASCAR, they actually choose hip-hop culture as a preference in music. They played hip-hop music while I was at the Daytona 500. Hip-hop is already there. It’s just about them actually getting involved more.

[Laughs] It does make sense, actually. You look at this initially and think, 'Why is Floyd actually doing that?' But Justin has struck a chord with kids and everybody else. Floyd looked at it as, having somebody around him from music culture will catapult him in viewership. You know, the first person who came out with Floyd was me. And, look, there’s a lot of interesting s--- goin’ on with Justin Bieber right now. [Laughs]

You’re a boxing promoter. Would you want Bieber walking one of your SMS Promotions fighters to the ring?

Yeah, but not a new guy -- an established fighter. A guy whose brand is developed can handle that [Bieber-related publicity]. It’s just an additional conversation piece. If we’re not talking about Floyd and his fights, we’re talking about Bieber being there. It just makes it more relevant.

Another hot trend has music titans taking active roles in sports, as owners and management types. Jay-Z jumped from Nets minority owner to agent, Justin Timberlake has a stake in the Grizzlies and you have your boxing promotion. What makes music artists think they can succeed in sports?

Well, for the most part, they kind of follow each other. Teams that these artists actually associate with are in the actual territory that they’re relevant in, and that they’re actually from. With the Nets, Jay-Z has a strong connection to Brooklyn -- and how much do the Nets have to spend on marketing in Brooklyn, and later to build Barclays Arena? See what I’m sayin’? People can feel like they’re associated to him. I think Usher had a portion of the team, too.

And for the artists, it’s good business. The sports business model is pretty healthy due to TV rights.

And whenever we have a chance to relax, we’re [tuning into] media. Even if you’re on vacation somewhere, there’s gonna be some sort of film, TV or music connected to what you’re doing to relax. And sports are a big part of what goes on on the networks because it’s a one-off event. You can’t re-do a basketball game. That’s the difference between music and sports. Music is a performance that repeats itself, until you revamp the entire show.

What’s the latest with SMS Promotions?

I have two fighters getting ready to fight on HBO. Shortly you’ll see Mikey Garcia versus Yuriorkis Gamboa. Following that, James Kirkland, we’re matchmaking him now. You’ll see that on HBO Sports.

Is the climb to the top of the boxing world more difficult than you thought it would be?

It’s not. You know what I think? There’s an “old boys club” in boxing and they don’t really like new people. [Laughs] I’m tellin’ you, this is true. I’ve never seen traditional business people have the thought process of, “If it’s not mine, destroy it.” The sport of boxing is more like, “If it’s not my fighter who’s becoming the man, destroy the other one.” That’s their intention. They end up destroying the guy who could’ve been the new big guy. So if you have a fighter who could be the next big star, you’ll end up feeling negative energy from multiple angles, multiple promoters who are trying to create a scenario that can damage you.

It sounds like your music gig. Much of hip-hip is about hating on the next guy.

It’s competitive. The difference between hip-hop and the mentality that’s running boxing is, there’s always ten guys in the Top 10 on the countdown. No matter how valuable you are to it, there will always be 10 in the Top 10. A lot of artists don’t accept it. I think when they have that tunnel vision and they can actually see that it keeps going without them, it allows them creatively to do things they normally wouldn’t do.

You started boxing at 11, competed as an amateur. Then you got in trouble. Do you ever wonder what might have been, had you stuck with it?

Oh, I don’t know. The only distraction that I had at that time was the constraints of finance, which forced me to look at other things in my environment, and that got me in trouble. But I think I’d be pretty good today. I’m still pretty physical now, know what I mean? But I’ve just been living vicariously through fighters. What made the relationship with me and Floyd be public -- Floyd was following me around since 2002. You just didn’t see us publicly around each other until I had time, because I had to deal with the business of the music business. I hadn’t released music in some time. It’s been almost four years since my last project.

When can we expect your next album?

Now that I have everything cleared up, I’m ready to release music, and I’m really excited about it. I got a project coming out: “Animal Ambition” will be out before the first quarter ends. It’s about the untamed desire to win.

Back to SMS, you have Carmelo Anthony selling your headphones. Dr. Dre has LeBron James to help sell Beats. Who do you like in a one-on-one game, to 10, between Melo and LeBron?

Man, you know what? Right now, I’d take Melo. Melo’s hot right now, baby. Just broke the [Madison Square Garden] record, 62 points. Melo’s not just selling my headsets. He’s an actual equity owner in the company now. He’s involved in a different way. It’s cool to have somebody with me who means something not just to sports, but overall. Him and [music producer and SMS-partner] Timbaland have been a great help.

Who wins between you and Dre in a one-on-one game to 10?

In basketball? [Laughs] That’d be good. Let’s get him out there. He can’t keep up with me. God damn it, I told you I’m physical! I’ll run circles around him.

Everybody is wondering where Melo will sign this summer. What has your pal and business partner told you about his free-agency thoughts?

Well, he hasn’t. And I tell him, “Don’t say nothing.” When we’re together, we talk about different things.

You told him not to tell you? You don’t want to be one of the few people on earth who knows Melo’s thought process?

Naw, because I’m gonna tell him to stay in New York! [Laughs] I want him to stay in New York, right here. But I don’t know -- I mean, L.A. is nice.

As a Knicks fan, I’m sure you want him to stay put, but as his business partner, would you be OK with the Lakers?

L.A. is definitely a nice spot. And Kobe will be back. I actually just saw him at the Knicks game and I hung out with Kobe after, and Meryl Streep.

Oh, ain’t nobody gonna top my photo. When I put it on my Instagram, I told them, see if you can beat this. [Laughs] It was interesting. We just ended up in the same place. It was actually Meryl’s first game. We came into this lounge area, where you hang out before the game, and they serve food and drinks, and then you watch the game. We sat down and talked and enjoyed it. I wanted to talk to Kobe during the game. We made eye contact, and he was like, when it’s done, come around and we’ll talk. As soon as the game was over, Kobe had some guys escort us to the back so we can actually speak to him. We took regular pictures first, and then I started playin’ around. I was like, “Hold up, we gotta get a lil gangsta back here, now.” But I only put up one photo.

I’m dying to know what you, Kobe and Meryl talked about.

We was talkin’ for a bit. We talked about [Streep’s film] “August: Osage County.” I told her, “You’re gonna win another award because you scared the s--- out of me in that movie!” [Laughs] She started laughing at me. I was like, “What the f---, man?! I ain’t gonna lie to you, Meryl, you kinda scared me with all that s--- in that movie!”

You wear a lot of hats, but let’s say you can have any job in sports, any job at all. What would you do?

Oh man, I don’t know. GM of the Knicks? Naw, I never see the general manager of the Knicks. I’m not sure that’s the right job. [Laughs] I’d have to be one of his athletes, if it’s a dream. And I’d be the MVP. [Laughs] Ya know, that victory moment, I wrote a song about it. It’s called “Winner’s Circle,” and it’s on the “Animal Ambition” project. That’s what the project is about. It’s about women, jealousy, people having that sense of entitlement, all these different things that surround us, and I think the victory moment where everything is going right, when you’re disciplined and you’ve put yourself through all of it, and then you get there -- it’s overwhelming to the point where grown men cry.

So in your dream scenario, next year Curtis “50 Cent” Jackson will be playing alongside Melo and you’ll both be crying in the winner’s circle in New York?

Or L.A.! If we get Kobe back, we gotta go to L.A., then, baby. Hold up, now, we do want to win some! It’s not all about the money. Players, they make interesting moves for that ring, because they’ve dreamed of it for so long. How long are they out there working for that ring? It’s definitely not all about the money.